RIO’s Shimmy Frog is designed around a compact foam body that balances buoyancy with controlled lateral movement. The foam is shaped to create a slightly flattened underside, allowing the fly to sit low on the surface while remaining fully afloat. Flexible rubber legs are positioned symmetrically to extend beyond the rear of the body, contributing continuous motion even with minimal line movement. The body’s side profile is tuned to encourage subtle side-to-side movement during slow retrieves, producing a gentle surface disturbance rather than an aggressive splash. Hook placement is recessed into the foam body to preserve alignment and reduce exposure. This construction results in a surface frog with consistent posture and controlled surface action.